The FG-X is the best mastering processor I have used to date. It can get the mixes very loud while maintaining a dynamic feel.

It has two sections. A Compressor and a Leveler.

The compressor is very transparent. It helps tame the mix before the final leveling stage.

However, the leveling section of the FG-X is the part that makes it great. It has LoPunch and Detail transient knobs that allow you to adjust how it will react to low and high frequency transients, mainly the kick and snare. Turning the knobs up lets the transients attack more, thus making the mix much more punchy.

It also has a dynamic perception knob, which what it does is right in the name, and it works really well. It also has an ITP slider (Intelligent Transient Preservation) that allows you to adjust between Hard and Smooth transients. I have mainly used it for aggressive styles of music and the Hard ITP settings work really well. All the transients of the drums and even the guitars hit really hard, making the mix feel very punchy and dynamic.

Another great feature is the "Constant Gain Monitoring" button. When enabled you can adjust the gain as much as you want, but the output volume will stay the same. This will save you from getting tricked into thinking the leveler is changing the sound when it's really just making the mix louder.

There are a couple downsides, however. The leveler section is very CPU intensive, so you may not be able to use it in-session if your computer isn't powerful enough of if your session already has a lot going on.

Also, unlike other plug-ins, the FG-X isn't one where you can just install and use it successfully right away. You really need to read the manual to get the sound you want, but it's an easy read.

The price is also a little high, but it does something I think a lot of other plug-ins don't do: Makes your mix loud while maintaining a dynamic feel.

Before we get started on this review I want to go into some back-story on myself.

I master records for a living.

I'm not a famous engineer with several Grammy's, though I have worked for a high profile software developer (Studio One Media) years ago, and one of the primary functions of what we developed was a mastering process which won a U.S. Tech award...resulting in other people winning Grammy's a few times over with what we were working on. (Fun's We Are Young used the "Aftermaster" process we designed as a finalizer for example.)

I do a lot of other things too...I write, run an indie record label...help artists get developed, consult on building recording studios, produce, engineer...mix.

But more than anything...I master albums for independent artists. It's been my primary source of income for 6 years.

I am very lucky that this is how I make a living...and I am uniquely qualified to review this particular software (Which I think is particularly useful and well designed.) so I want to dive into this review with the context of my back-story as a pro engineer in mind for any readers who might want to really think about incorporating this software, the Slate Digital FX-G, into their system.

The Loudness Wars Vs. Tasteful Transient Response Control found with the FX-G:

Like it or not, we have to make our masters loud in certain respects if we wish to compete in mainstream media; that being the case, we might as well do so in the way that causes least possible damage to the integrity of our source material. Making a mix louder usually involves both ironing out ‘macro’, or medium- to large-scale dynamic contrasts — such as the gulf in level between a quiet verse and a busy chorus, or between the impact of a loud snare hit and the decay creating space after it — as well as taming ‘micro-dynamics’, the momentary peaks that are often known as transients. The former are usually tackled using a conventional compressor, while there are various approaches to dealing with transients. Traditionally, one would use a peak limiter (in other words, a compressor with a very fast attack and release, and an infinite ratio setting); though some engineers find it more forgiving to apply other forms of signal distortion such as tape-style saturation, or simply to clip the input of an A-D converter if they're not perfectionists about it, but there is always a trade-off between sound quality and the degree by which transients can be attenuated and controlled in mastering...so please consider that pro mastering engineers who devote their lives to trying to improve their abilities to control such aspects of a recording are merely trying to put a finishing touch to something most of the time.

All things being equal if the mix is solid already the last thing you want to do is lose the balance of what's good about it, but the consequences of turning our albums up as loud as they have been in recent years is something we cannot ignore.

Headroom before distortion is constantly sacrificed in order to meet professional broadcasting standards, and this trend, while disturbing, has only grown over the last twenty years in popular music culture.

Now, maybe you're new to recording and you don't think about things like "Headroom". So I'm going to make a key list of technical terms for you to follow before we proceed.

Mastering components I can measure and control with the FG-X:

Headroom: Defined as the physical limits of volume for a recording before it starts to distort, or the amount by which the signal-handling capabilities of an audio system exceed a designated level known as Permitted Maximum Level (PML). Headroom can be thought of as a safety zone allowing transient audio peaks to exceed the PML without exceeding the signal capabilities of an audio system (digital clipping, for example). Various standards bodies recommend various levels as Permitted Maximum Level.

Digital Headroom: In digital audio, headroom is defined as the amount by which digital full scale (FS) exceeds the permitted maximum level (PML) in dB (decibels). The European Broadcasting Union (EBU) specifies a PML of 9 dB below 0 dBFS (-9 dBFS), thus giving 9 dB of headroom. An alternative EBU recommendation allows 24 dB of headroom, which might be used for 24-bit master recordings where it is useful to allow more room for unexpected peaks during live recording. Failure to provide adequate headroom can bring about clipping of brief, higher-level transients.

Dynamic Range: (DR for short.) In music, dynamic range is the difference between the quietest and loudest volume of an instrument, part or piece of music. In modern recording, this range is often limited through audio level compression, which allows for louder volume, but can make the recording sound less exciting or live.[30] Popular music typically has a dynamic range of 6 to 10 dB, with some forms of music having as little as 1 dB or as much as 15 dB. Though many records are being pushed to a DR of 4-2 dB in recent years (Death Magnetic by Metallica for example was extremely controversial in that people found it to be a distorted and unlistenable mess. It's DR had exceeded any headroom the recording was capable of retaining at such low levels before digital zero.)

Apparent Volume: This term refers to things sounding louder than a meter might actually read them to be. Mainly due to frequencies being highlighted in a mix several times over, a causing them to jump out, but not affect basic metering for average peak levels too much. Apparent Volume can be the difference between a balanced mix, and something that feels small and crushed even though it measures out to be incredibly loud.

Personal notes:

The main thing I get from using the FG-X in the field is a much more uniform control of apparent volume on whatever I stick it on. If I put it on a drum bus alone for example things feel 3D...like they're flying out of the speaker if I tweak it right. As if the snare drum is next to my head! But I also get acute control of overall volume, so this apparent volume doesn't have to be pushed to loudness war loud when in use!

*The tightrope balance of always trying to get things as loud as you can in order to compete with other loud recordings is a difficult one. For ever mastering engineer who is impassioned about retaining dynamics like myself there are countless people who are just trying to make a living, or even worse...merely imitate recordings they like without much by way of thought.

Without getting into the debate of how loud is "too loud" I want to make a caveat...optimal loudness should in fact vary genre to genre, but in exchange for doing more research on the subject I submit that you will often find new albums in recent years that are starting to break the mold like Jack White's Blunderbuss or the recent Daft Punk LP Random Access Memories, both of which are far quieter than most top 40 LP's and both of which are in fact #01 records on billboard!

That's why something like FX-G is so significant to my mind. considering it's features, I now have one plugin which can give me all the sonic benefits of hard limiting and high volume presence in a loud master, while also keeping my dynamic range in a much more controlled and usually lower volume than one would think in order to achieve greatness.

Yes, it can just make things straight huge and blow some speakers, but the level of control offered here is something altogether unique to one plugin.

Features (Paraphrased From The Manual):
The FG-X Dynamics Rack consists of two main processors, the FG Comp and the FG Level.

FX-G Compressor:
The FG Comp is a world class mastering compressor that combines several compression topologies to create the ultimate in transparent dynamic control. It's an extremely transparent compressor aimed at mixbuss and mastering duties. Its algorithm is based on two different compression topologies, photo optical cell, and VCA. Both of which it mimics qualities of simultaneously.

Power (Button)
Nothing to it, this is a hard bypass for the Compressor section.

Release
On very slow Attack and Release parameters, the FG Comp acts like a leveler, as if someone moves a gain slider according to the input level. The leveler mode of the FG Comp algorithm has been designed to retain all the punch and original transients of the mix, while reacting in an intelligent way to sudden global loudness changes in the audio. This mode can be used in 2 ways:

A. With a high ratio and threshold, to prevent too high RMS levels in loud moments of the song.B. With a low ratio and threshold, in order to reduce the difference between the relative RMS levels throughout the song.

Ratio (Variable from 1:1dB to 20:1dB!)

Threshold

Analog Style Metering with 3-way switching (Input, Output, and Gain Reduction)
The In/Out metering options display the same settings than the Metering Section options. There are two additional options:

A. Match Metering Section settings. The FG Comp metering will then have the same display parameters than the Metering Section.B. Match Output Level. The FG Comp metering level will be displayed according to the RMS Reference Level and the FG Level Gain. This allows having a RMS level display which matches the final output level of your master, and thus visualizing the FG Comp and Metering Section levels
around the same 0dB reference RMS value.

FX-G Level:
The FG Level is a loudness processor that uses a revolutionary new algorithm to add level without adding degrading artifacts. The FG Level also contains a dithering algorithm, which retains the sound of your higher bit rate audio files in their final 16 bit output.

Power (Button)
Nothing to it, this is a hard bypass for the Level section.

Settings (Button)
The Settings tab to the left of the TRANSIENT knobs allows you to link both parameters of the "Transients" section.

The first section of FG Level is the TRANSIENT section. This section has two controls, "LoPunch", and "Detail". LoPunch can raise the level of the low end punch of the mix a/k/a the kick drum level. Detail will raise the level of the high end punch, such as snare drum. These controls are intended to be used to customize the amount of final transient articulation in the final master. It is recommended to leave them all the way down, and to apply them AFTER the GAIN.

Gain (Variable)
The gain knob controls how much gain is added to the mix. As peaks approach the ceiling, they are processed via ITP as described earlier. The GAIN automatically goes to a built in ceiling which can be adjusted from 1 to 20dB.

Constant Gain Monitoring (Button)
The Constant Gain Monitoring button will decrease the output of the processor by the same amount as you add via the GAIN knob. This allows you to easily compare the original mix vs. the processed mix by enabling and disabling the power button on the FG Level. This simple feature can help you evaluate what FG-X is doing, without the added gain inherent in the process. This way, you are comparing the affected and unaffected audio.

Intelligent Transient Perception (ITP - Variable from "HARD" to "SMOOTH")
The ITP slider can be considered the most important control in the FG Level. By moving the ITP slider up or down, you change the global characteristics of the saturation curves created by the ITP processor. When you raise the slider, the ITP processor uses more aggressive curves throughout the frequency spectrum, adding a slightly “hard” sound to the transients. The lower you push the ITP slider, the gentler the saturation curves become, making the final master sound smoother. Generally, placing the slider in the middle leads to the most transparent results. For modern pop, rock, and metal, moving the slider up is recommended for the most punch. For big bassy R&B or hip hop, the middle or slightly lower settings can retain a lot of sub bass.

Dither On (Button)
Nothing to it, this is a hard bypass for the Dither.

Dither & Ceiling Settings (Button)
By hitting this button, you are given a tab to customize your ceiling setting and dither bit value. It is recommended to keep the ceiling from 0.3 to 0.1. For CD masters, make sure to put the dither settings at 1. You can also change your output Bit-rate from 16Bit to 24Bit...or something lower if you're trying to make an old 8Bit video game sound I suppose.

Metering Section:

Power (Button)
Nothing to it, this is a hard bypass for the Level section.

Settings (Button)
The global metering options let you adjust:

A.The Reference RMS Level which will be used as the 0dB display reference of the metering section VU meters.B.The Constant Gain Monitoring behavior regarding the level display. Keep it off will just keep the metering the same display level as if Constant Gain monitoring button was turned off.C.Bargraph Peak Meter & Bargraph RMS Meter, which adjusts the release and maximum value hold time. You can adjust for each of the Settings. (There are more sub-setting parameters under this tree, but I will skip over them since they're outlined exhaustively in the manual, and most of them are not things you'd want to adjust under normal circumstances.)

I use a Manley Massive Passive and a pair of Germanium Compressors on my 2Bus mainly...sometimes with a Great River EQ-2NV. My problem is I don't have an analog limiter I feel good enough about pulling the trigger on for this purpose within my budget, though the main thing with my analog gear is when I get that extra width and depth I want to hang onto it. I'm not losing anything, if anything we go just a little bit wider again with the FG-X. I do hear some processing or maybe digital mimicry of harmonic distortions / non-linear phase response. Though it's a naturally musical thing with the chain I've got. Everything seems to be working better than ever with it in-line. The key words here are signal integrity.

After buying FX-G I wound up shooting out most of the usual digital 2Bus suspects comprehensively...FX-G wins for having the widest and most detailed stereo image (rivaling some of the best in analog gear even in that department), and for sheer flexibility in usage (it's great even when just using it on tracks or a drum bus for example), but when you factor in the ability to retain transient response to the degree it can while sporting some of the most comprehensive metering I've ever seen in a single plug-in, let alone in a finalizing limiter...it starts to really beef up the case that this plug has knocked Ozone, L2 and L3, and Massey etc. (Further down I'll explain why it's superior to these other designs by comparison) It's king of the bloody mountain when it comes to sheer musicality since it's designed to change knees against transient response and to soft clip rather than limit a range of peaks you set, so at when using a more relaxed "Dynamic Perception" variable on a more "Smooth" setting you get a very natural sounding transient response that doesn't feel compressed at all.

The dithering is aces on this thing, but most of the color comes from the compressor stage or the Dither...both of which can be hard bypassed if you wish to push the FX-G Level section for makeup gain transparently. The limiter seems fairly neutral on it's own. Actually the difference in "color" is that this plug-in very-nearly always makes your mix sound a bit better, more refined, and downright exciting as soon as it's activated! (*Because if it doesn't then you would have to be already clipping, or way to loud, and would need to back off your gain going in.) When I insert the FG-X on a bus it's not so much that things get colored immediately, but the stereo spectrum widens ever so slightly in a good way, allowing the center spectrum to sit in a more 3-D manner that makes sense to my ears immediately...and it does all this without sacrificing any depth of field or killing how "tall" things can be in terms of transient response to boot! (Now will it make me coffee and field my calls? ) Otherwise I'm hearing the mix I put into it without any artifacts...if I compress first lets say to -2dB to -4dB (which would normally be the hardest I'd ever want to crush program material...to a truly aggressive setting to my mind for mastering, which would only be useful in a restoration session of some kind.), I'm not losing the transient responses or the "height" as long as the leveling amplifier / limiter is tailored to taste against the sound to distort transient response rather than just merely compress it all...it's a pretty remarkable piece of kit honestly. I would buy an analog version of this plug-in if it existed just to hear them side by side. Now to be fair, I haven't felt the need to try to crush things as hard as I can yet, but I don't think that's the point of something like this. Normally no compression to around -2dB is MORE than enough to tame and control things if a mix is well put together...and with my transient response in check I don't have to lose the swing of the groove in order to brick-wall limit. From the video I can see you can get away with more aggressive crushing, but to be fair to anyone who is skeptical, I would say that unless you were feeding in a parallel bus I wouldn't ever want to get that crazy with it.

Lastly how it handles bottom end is insanely well thought out. It's not just mid-range to high frequency transients that benefit from this design and the groove always wins as long as you're willing to chase it.

It would take a chain of extremely expensive boutique and sometimes even customized gear to mimic the FG-X in an analog environment, *including the extensively well laid out metering, which happens to be one of it's finest features. Though I'm not sure it would be all that much better for it if this exact sonic signature did exist in an analog format since the build quality would have to be literally incredible (Think like a cross between a Pendulum PL-2 or Foote Control Systems PS3 with maybe a compression stage by Crane Song.) I have always hated most of the mainstay staples of digital brick wall limiting: OZONE (Dulls the mid-range immediately until it feels plastic and digital, making it all too easy to overcompensate until your mids grow to be too harsh) / Massey 2007 (Thins the bottom end as soon as it's inserted which makes you have to overcompensate to re-balance your low-end response at the end of your mix/master if you're not careful.) / L2 (keeps the overall balance without losing your mix, but blurs your transient responses until they're near meaningless in context with how loud you are if you don't run your mix hot going into it.) If you're a working class stiff like me...more often than not, you get stuck with this list of the usual suspects and/or all the other plug-in solutions which are just sort of in-between those three archetypes sonically in most project environments. Plus all of these options can't do what FG-X actually does when it comes to preserving transients, let alone your original mixes balance!

CONCLUSION:

As previously state earlier...people will always try to crush things in order to feel competitive to real mastering engineers in the top facilities without really thinking about what professional mastering as a process actually entails, so...most of them don't really break down what the best of the best are doing on a daily basis in order to push the boundaries of mixing and mastering at what has now become a highly competitive professional level. Though it's not "idiot-proofed" FX-G is something that has never existed before for people who want to do a professional job...and for that I'm grateful. Since FG-X is a plug-in that truly shines as much as anything analog I own, I will never have to worry about using sub-par final limiting on a mix again as long as I have my ILOK with me. So anyone who has tried the FG-X briefly and just didn't get it. I urge you to reconsider and take a second look. I don't work for Steven or either of his companies, but as a former mastering software designer I've spent just over a month with this now putting it through it's paces...and I've been wondering where it's been all my life the whole time.

I'll admit, I've been a huge fan of Steven Slate since his first products hit the virtual shelves. I have always found Slate's tools to be cost-effective, intuitive, and deadly effective. The FG-X is no different, even years after its initial release.

Quite honestly I have never used a limiter, software or otherwise, that can match the FG-X for its musicality, transparency, micro-dynamics preservation, punch, and character. Prior to putting the FG-X in my arsenal it would take a number of plugins, aux busses, and so forth to reach a final product I was proud to put my name on. With the FG-X, those days were immediately over.

Unlike a lot of limiters, the FG-X actually improves the sound just by pumping stuff through it. There is some serious black magic going on underneath the hood courtesy of code-guru Fabrice Gabriel!

While I could sing the praises of the FG-X for mastering all the live-long-day, I find that it is useful in many non-mastering applications as well. Due to its ability to fine-tune the "dynamics DNA" of audio the FG-X is a powerful tool for mixing. The ability to manipulate transients, both low ("lo punch") and high ("detail") allow for an almost "dynamics-eq" approach. Need to pound some chests with a kick drum? Dial in some lo-punch. Want to add sparkle and gllitter to your overheads? Add some detail to it. Easy! Feel the need to push something forward in the mix? Tweak the dynamic perception and it'll toe the line where you need it to go. Have the urge to slow down some transients, imparting an old-school, crappy slew-rate preamp feel? The ITP is your solution--just pull the lever downwards to "soft." Want to impart that "cuts like a diamond" edge to a signal? Adjust ITP to "hard." None of these tweaks involve boosting the gain at all! Just adjust to taste as need-be.

Furthermore, on the mixing side of things, I find the FG-X useful for limiting critical elements like kick, snare, bass, and even guitar. Granted, this is perhaps overkill, but the FG-X is so transparent, so euphonic, and so effective I cannot help myself. Granted, you're going to burn some serious CPU doing this.... which is why I often "print" these tracks and import them into a session for additional mix-work. (Of course, keep the originals just in case.)

There are a lot of other limiters on the market. They all sound pretty good. Most of them work as advertised. However, as of 2014, I still believe the FG-X has them all cornered. This, my friends, is still the high water mark for limiting, whether it is software or hardware. This is the gold standard.

I highly recommend adding this plugin to your repertoire. If your tastes are anywhere near mine you will quickly exclaim: "This is the one."